JP4429863B2 - Flux-cored copper-plated wire for gas shielded arc welding - Google Patents

Description

  The present invention relates to a flux-cored copper-plated wire for gas shielded arc welding, and in particular, when a long and long conduit cable is used for welding for a long time, the wire feedability is good and the wear of the tip is reduced. The present invention relates to a flux-cored copper-plated wire for gas shielded arc welding that is less arc stable.

  In general, a flux-cored wire for gas shielded arc welding is a seam-type flux-cored wire having a cross-sectional structure having a seam 3 filled with a flux 2 as shown in FIGS. 1 (a) and 1 (b). And the small diameter (0.8-1.6 mm) of the seamless type flux-cored wire having a cross-sectional structure shown in FIG.

  The seam-type flux-cored wires shown in FIGS. 1 (a) and 1 (b) have seams 3 and therefore cannot be plated with copper on the wire surface and cannot be reduced in diameter by wet wire drawing. Therefore, a metal soap or the like as a lubricant is used to reduce the diameter by dry wire drawing, and then a step of removing the lubricant on the surface of the wire (baking treatment) is required, and the copper plating treatment step can be omitted, but a complicated operation is required.

  As a technique for obtaining sufficient welding workability without the baking treatment, for example, in Japanese Patent Laid-Open No. 5-23731 (Patent Document 1), an appropriate amount of polytetrafluoroethylene, molybdenum disulfide, graphite, mica, sericite and talc is used. There is disclosed a flux-cored wire that is dry-drawn with a contained solid lubricant and adheres an appropriate amount of the lubricant to the surface of the wire.

  However, when welding using the above-mentioned flux-cored wire, the solid lubricant on the surface of the wire is peeled off due to friction in the conduit tube included in the conduit cable. Accumulation increases the feeding resistance, the wire feeding performance is deteriorated, and the arc becomes unstable. Further, since the wire surface is not plated with copper and is reduced in diameter by dry drawing, the roughness of the wire surface is large, so that the tip is consumed by friction with the wire and the arc becomes unstable.

  On the other hand, the seamless type flux-cored wire shown in FIG. 1 (c) has less chip wear and stable arc because the wire surface is plated with copper. In order to improve the feeding property of the wire having the copper plating, for example, in Japanese Patent Application Laid-Open No. 61-27198 (Patent Document 2), a recess is provided on the wire surface using a shot having an average particle diameter of 50 to 750 μm. Japanese Patent Application Laid-Open No. 8-99188 (Patent Document 3) has a recess and a vertical groove on the wire surface, and Japanese Patent Application Laid-Open No. 10-249576 (Patent Document 4) has a wire surface roughness Ra of 0.1. In each case, a technique of holding a solid lubricant or a liquid lubricant in a recess on the surface of the wire is disclosed.

  However, when welding for a long time using the aforementioned copper-plated wire, the copper plating at the corners of the concave portion of the wire surface peels off due to friction in the conduit tube, and if scraped for a long time, the copper scraps in the conduit tube become solid lubricant. In addition to this, the accumulated resistance increases, the wire feeding performance deteriorates and the arc becomes unstable, which is not satisfactory.

JP-A-5-23731 JP-A 61-27198 JP-A-8-99188 Japanese Patent Laid-Open No. 10-249576

  The present invention provides a flux-cored copper for gas shielded arc welding which has good wire feedability and less wear on the tip and stable arc even when welding is performed for a long time using a soft and long conduit cable. An object is to provide a plated wire.

The gist of the present invention is an arithmetic average roughness Ra of the surface roughness measured in the direction of 30 ° with respect to the longitudinal direction of the wire surface in a flux-cored copper-plated wire for gas shielded arc welding formed by filling a steel outer shell with a flux. 0.04 to 0.12 μm, and the surface of the wire contains 0.005 to 0.50 g of molybdenum disulfide per 10 kg of wire and 0.008 to 0.15 g of lecithin and / or phosphatidylethanolamine , and the balance is room temperature. in to 0.5~2.5g it has a lubricant consisting of lubricant liquid in total, gas shielded arc welding flux cored copper plating wires, wherein the particle size of molybdenum disulfide is 1.0μm or less It is in.

  According to the flux-cored copper-plated wire for gas shielded arc welding of the present invention, even when welding for a long time using a soft and long conduit cable, the wire feedability is good and the tip wear and Spatter generation is small and welding with stable arc is possible.

  In order to solve the above-mentioned problems, the present inventors have made various studies on the welding wire surface state and the feed lubricant applied to the wire surface. As a result, using a soft and long conduit cable with copper plating on the wire surface and applying an appropriate amount of finely divided molybdenum disulfide and lubricating oil that is liquid at room temperature with limited surface roughness It has been found that even when welding for a long time, the wire feedability is good, the tip wear is extremely reduced, and a stable arc can be obtained.

  Copper plating on the wire surface reduces the frictional resistance in the conduit tube and improves the electrical conductivity at the tip of the tip to stabilize the arc. Furthermore, even when welding for a long time, the tip wear is extremely small and a stable arc can be maintained. However, if the calculated average roughness Ra of the surface roughness measured in the direction of 30 ° with respect to the longitudinal direction of the wire surface defined in JIS B0601-1994 exceeds 0.12 μm, the copper on the surface of the wire is caused by friction in the conduit tube. If the plating is peeled off and welding is performed for a long time, copper scraps are accumulated in the conduit tube, the feeding resistance is increased, the wire feeding property is deteriorated, and the arc becomes unstable. Moreover, the amount of wear of the tip increases with long-time welding, and the arc becomes unstable.

Copper plating improves the electrical conductivity, lubricity and wear resistance of the chip, and also has the effect of improving rust prevention. The plating thickness is preferably about 0.3 to 1.2 μm.
Note that when the calculated average roughness Ra of the surface roughness measured in the direction of 30 ° with respect to the longitudinal direction of the wire surface is less than 0.04 μm, the copper plating does not peel off, but the feeding roller portion of the wire feeding device The wire slips and the arc becomes unstable.

Next, the lubricant applied to the wire surface contains 0.005 to 0.50 g of molybdenum disulfide per 10 kg of wire, 0.008 to 0.15 g of lecithin and / or phosphatidylethanolamine , and the remainder is liquid at room temperature. A total of 0.5 to 2.5 g (hereinafter referred to as “g / 10 kgW”) of the lubricant composed of the lubricating oil.
Molybdenum disulfide suppresses the feeding resistance in the conduit tube and improves the wire feeding property. When the molybdenum disulfide is less than 0.005 g / 10 kgW, the feeding resistance increases in the conduit tube, and the wire feeding property becomes poor. Conversely, if molybdenum disulfide exceeds 0.50 g / 10 kgW, the arc becomes unstable and the amount of spatter generated increases.

In addition, it is preferable that the particle diameter of molybdenum disulfide is 1.0 μm or less because the feeding resistance is reduced and the wire feeding property is improved.
Lecithin and / or phosphatidylethanolamine have the effect of uniformly dispersing molybdenum disulfide on the wire surface by coexisting with a lubricating oil that is liquid at room temperature, which will be described later. When lecithin and / or phosphatidylethanolamine is less than 0.008 / 10 kgW, molybdenum disulfide on the wire surface does not adhere uniformly, and there is a part where the feeding resistance increases in the conduit tube. Becomes defective. Conversely, when lecithin and / or phosphatidylethanolamine exceeds 0.15 g / 10 kgW, the amount of spatter generated increases.

The lecithin and phosphatidylethanolamine referred to in the present invention mean those mainly composed of lecithin ( phosphatidylconone), phosphatidylethanolamine and the like. powder form containing Jill ethanolamine about 95%, there such as lecithin and phosphatidyl ethanolamine about 65% and vegetable oils such as soybean oil as a pasty containing about 35%, be either used Among them, lecithin obtained from soybean oil is preferable.

  Lubricating oil, which is liquid at room temperature in the lubricant, has a coating on the wire surface, complements the lubricating action of molybdenum disulfide during wire feeding, and improves wire feeding properties. The lubricating oil may be animal or vegetable oil, mineral oil or synthetic oil. Palm oil, rapeseed oil, castor oil, pig oil, cow oil, fish oil, etc. can be used as animal and vegetable oils, and machine oil, turbine oil, spindle oil, etc. can be used as mineral oils. As the synthetic oil, hydrocarbon type, ester type, polyglycol type, polyphenol type, silicone type and fluorocarbon type can be used. In order to further improve the lubricating performance, lubricating agents such as various fatty acids and phosphorus-based, halogen-based, and sulfur-based extreme pressure additives may be added to the lubricating oil, and the oxidation of the lubricating oil is prevented. Additives (antioxidants) may be added.

The total amount of the lubricant contained on the wire surface is 0.5 to 2.5 g / 10 kgW of the molybdenum disulfide, lecithin and / or phosphatidylethanolamine and the lubricating oil which is liquid at room temperature. When the total amount of the lubricant is less than 0.5 g / 10 kgW, the feeding resistance increases in the conduit tube, and the wire feeding property becomes poor. On the other hand, if it exceeds 2.5 g / 10 kgW, the wire slips at the feeding roller portion, and the arc becomes unstable.

  The flux-cored copper-plated wire for gas shielded arc welding of the present invention is manufactured by, for example, manufacturing a seamless wire strand by the method for producing a flux-cored wire described in Japanese Examined Patent Publication No. 4-72640, and then plating the surface of the wire for wet stretching. The diameter of the wire is reduced to control the diameter reduction rate to obtain the desired wire surface roughness, and the finished surface is drawn or the supply lubricant is applied to the surface of the wire after finish drawing.

Hereinafter, the effect of the present invention will be specifically described with reference to examples.
A spool-wound wire was manufactured by changing the surface state and the lubricant coating amount of a seamless flux-cored wire (JIS Z3313 YFW-C50DR, flux filling rate 13%) having a wire diameter of 1.2 mm shown in Table 1.

  For each prototype wire, wire feedability, chip wear and spatter generation were investigated. The wire feedability and the tip wear amount were evaluated using the apparatus shown in FIG. In FIG. 2, the spool winding wire 5 set in the feeder 4 is pulled out by the feeding roller 6, and fed from the torch 8 at the tip of the spool winding wire 5 to the chip 9 through a conduit tube included in the conduit cable 7. Then, bead-on-plate welding is performed between the tip 9 and the steel plate 10. The conduit cable 7 has a length of 6 m and is provided with a bend 11 in which two loops with a diameter of 75 mm are formed in order to provide a feeding resistance. The feeder 4 includes a detector (not shown) for the peripheral speed Vr (set wire speed) of the feed roller and an actual wire speed Vw detector 12.

  The slip ratio SL of the wire feedability evaluation index is represented by SL = (Vr−Vw) / Vr × 100. Further, the reaction force that the wire receives from the conduit tube during wire feeding by the load cell 13 provided in the feeding roller portion was detected as the feeding resistance R. Welding is performed for 45 minutes under the welding conditions shown in Table 2 using a new conduit tube for each prototype wire, and the average value is measured by measuring the slip rate SL and the feeding resistance R for 30 minutes from the start of welding to the end of welding for 15 minutes. Asked. When the slip rate SL was 10% or less and the feed resistance R was 6 kgf or less, it was determined that the wire feedability was good. Further, the wear amount of the tip was measured by using a new tip (inner diameter: 1.4 mm) for each prototype wire and measuring the inner diameter of the portion with the greatest wear after welding. The chip wear amount was evaluated as good when the wear amount was 0.05 mm or less.

  The spatter generation amount was 5 under the welding conditions shown in Table 2 by bead-on-plate welding using a copper collection box without replacing the conduit tube and the tip after the wire feeding property and tip wear test were completed. Spatter collected by round welding (one welding time of 1.5 min) was converted to a generated amount per minute. The amount of spatter generated is 1 g / min or less, the arc is stable, and the workability is good. The results are summarized in Table 1.

In Table 1, wire No. 1 to 8 are examples of the present invention, wire Nos. 9 to 17 are comparative examples.
Wire No. which is an example of the present invention. 1 to 8 have copper plating, the arithmetic average roughness Ra of the surface roughness measured in the direction of 30 ° with respect to the longitudinal direction of the wire surface is appropriate, and molybdenum disulfide, lecithin , which are lubricants on the wire surface, and Since the adhesion amount of phosphatidylethanolamine and the total amount of lubricant including lubricating oil and the particle size of molybdenum disulfide are appropriate, the slip rate SL and the feeding resistance R are low and the wire feeding property is good. In addition, the results were extremely satisfactory, for example, the amount of chip wear and the amount of spatter generated were small and the welding workability was good.

The wire No. 9 in the comparative example has a low arithmetic average roughness Ra of the surface roughness measured in the direction of 30 ° with respect to the longitudinal direction of the wire surface, so that the wire slips at the feeding roller portion of the wire feeding device. The slip rate SL was high and the arc was unstable.
Since the wire No. 10 has a high arithmetic average roughness Ra of the surface roughness measured in the direction of 30 ° with respect to the longitudinal direction of the wire surface, the copper plating on the surface of the wire is peeled off by friction in the conduit tube, Copper scraps were accumulated and the feeding resistance R was large, and the wire feeding performance was deteriorated. Moreover, the amount of wear of the tip was large and the arc became unstable.

Wire No. 11 has less molybdenum disulfide, and wire No. No. 13 has less lecithin , and wire no. No. 15 has a small total amount of lubricant, so that in all cases, the feeding resistance R was large, the wire feeding performance was deteriorated, and the arc became unstable.
Wire No. No. 12 has a large amount of molybdenum disulfide. Since No. 14 had a lot of lecithin , spatter generation amount increased in all cases.

The wire No. 16 has a high slip ratio SL because the total amount of lubricant is large. Further, since the particle diameter of molybdenum disulfide is large, the feeding resistance R is large, the wire feeding property is deteriorated, and the arc becomes unstable.
Since the wire No. 17 was not plated with copper on the wire surface, the wire feed resistance R was large, the tip wear amount was large, and the arc was unstable.

It is the schematic diagram which showed the cross-sectional structure example of the flux cored wire. It is a figure which shows the apparatus of the wire feeding property test in the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel outer skin part 2 Flux 3 Joint of steel outer skin part 4 Feeder 5 Spool winding wire 6 Feeding roller 7 Conduit cable 8 Torch 9 Tip 10 Steel plate 11 Bending part of conduit cable 12 Actual speed detector 13 of wire Load cell


Patent Applicant Nippon Steel & Sumikin Welding Industry Co., Ltd.
Attorney Attorney Shiina and others 1

Claims (1)

In a flux-cored copper-plated wire for gas shielded arc welding formed by filling a steel outer shell with a flux, the arithmetic average roughness Ra of the surface roughness measured in the 30 ° direction with respect to the longitudinal direction of the wire surface is 0.04 to 0. .12 μm, and 0.005-0.50 g of molybdenum disulfide per 10 kg of wire and 0.008-0.15 g of lecithin and / or phosphatidylethanolamine per 10 kg of wire on the wire surface, the balance being liquid lubricant at room temperature comprising lubricant 0.5~2.5g have a total, gas shielded arc welding flux cored copper plating wires, wherein the particle size of molybdenum disulfide is 1.0μm or less.

Images